Juvenile psammomatoid ossifying fibroma with aneurysmal bone cyst in the posterior mandible

First presentation of a frameshift mutation in the SETD2 gene of a juvenile psammomatoid ossifying fibroma (JPOF) associated with an aneurysmal bone cyst

Background

The rarity of juvenile psammomatoid ossifying fibroma (JPOF) and lack of cytogenetic studies prompted us to report a novel SETD2 gene mutation in a benign odontogenic tumour.

Case presentation

A 21-year-old man presented with a hard, expanded mandibular cortex. Computed tomography revealed multilocular radiopacity in the mandible; this was reconstructed via segmental mandibulectomy using a vascularised iliac crest flap. Based on the clinical and histological findings, we diagnosed JPOF associated with an aneurysmal bone cyst. Microscopically, the solid area was characterised by many rounded or angular ossicles in a cellular fibrous stroma. The stromal cells were spindle-like or stellate. Next-generation sequencing detected a frame shift mutation of the SETD2 gene, while the copy number was normal.

Conclusions

Our findings suggest further genetic studies should be performed to assess whether this mutation is related to tumour genesis. 

Comparison of Hematoxylin and Eosin Stain with Modified Gallego's Stain for Differentiating Mineralized Components in Ossifying Fibroma, Cemento-ossifying Fibroma, and Cementifying Fibroma

Objective

The nature of calcifications in fibro-osseous lesions is difficult to differentiate under hematoxylin and eosin (H and E) stain and could be misleading. Special stains could be used. Modified Gallego's stain is a differential stain for hard tissues, which has been discussed recently in the literature.

Methods

Retrospective study was done from June to December 2015 to differentiate various types of mineralized tissues in ossifying fibroma (OF), cemento-OF (COF), and cementifying fibroma (CF), using modified Gallego's stain and its correlation with H and E stain. Control group comprised of decalcified section of bone, tooth, and odontoma, stained with modified Gallego's stain. Study group comprised of 30 lesions (10 OF, 10 COF, and 10 CF) stained with both modified Gallego's stain and H&E stain. This study did not have any numerical data; therefore, no appropriate statistical test could be performed. Hence, cross tabulation of the categorical data was used followed by descriptive statistical analyses. Results were presented on continuous measurements using mean ± standard deviation, and results on categorical measurements were presented in number (%).

Results

Modified Gallego's staining showed that, out of 10 cases of OF, 9 cases were interpreted as OF; one case of juvenile psammomatoid OF was interpreted as juvenile psammomatoid COF. Out of 10 cases of COF, 4 cases were interpreted as OF. Out of 10 cases of CF, 2 cases were interpreted as COF and 3 cases as OF.

Conclusions

Fibro-osseous lesions are difficult to diagnose using H and E staining alone. Modified Gallego's stain could be a best adjunct.

Recurrent juvenile psammomatoid ossifying fibroma with secondary aneurysmal bone cyst of the maxilla: a case report and review of literature

Juvenile ossifying fibroma is a benign fibro-osseous lesion commonly affecting the extra-gnathic craniofacial skeleton of the young individuals. The psammomatoid and trabecular variants are its two histopathological subtypes having distinctive clinico-pathological characteristics. Secondary aneurysmal bone cysts are frequently reported to arise in the pre-existing fibro-osseous lesions but rarely reported in the psammmomatoid variant of the juvenile ossifying fibroma. Such hybrid lesions, especially massive in size, tend to exhibit a greater aggressive growth potential and higher recurrence rate and mandate complete surgical removal of the lesion along with a long-term follow-up. The objective of this case report was to present a rare incident of recurrent psammomatoid ossifying fibroma associated with a secondary aneurysmal bone cyst in the maxillary jaw bone of a young patient and review the similar published reports in the English literature.